1. Introduction
Biomaterials are based on a broad range of materials, such as organic polymers, metals and ceramics including both sintered and chemically bonded ceramics (silicates, aluminates, sulphates and phophates). The biomaterials can be made prior to use in the body in a conventional preparation of the material. The need for in situ in vivo formed implant materials makes the chemically bonded ceramics especially potential as biomaterials. These ceramics include room/body temperature formed biomaterials with excellent biocompatibility. Ca-aluminate as a biomaterial has been evaluated for over two decades with regard to general physical, mechanical and biocompatible properties. The Caaluminate based materials exhibit due to their unique curing/hardening characteristics and related microstructure a great potential within the biomaterial field. The presentation in this chapter aims at giving an overview of the use of Ca-aluminate (CA) as a biomaterial within odontology, orthopaedics and as a carrier material for drug delivery. The examination deals with aspects such as; the chemical composition selected, inert filler particles used, early properties during preparation and handling (working, setting, injection time, translucency, radio-opacity), and final long-term properties such as dimensional stability and mechanical properties (fracture toughness, compressive and flexural strength, hardness and Young´s modulus). One specific topic deals with the sealing of the Ca-aluminate biomaterials to tissue - a key in the understanding of the mechanisms of nanostructural integration.